Under fully-reversed, variable amplitude loading with a straight-line spectrum, the fatigue strength could be improved by HFMI.
To establish baseline fatigue behavior, several virgin specimens were tested under fully-reversed strain control and constant amplitude fatigue torsional loading up to failure.
This work explores the applicability of the scaling parameter to specimens under fully-reversed (i.e. R = −1) cyclic fatigue loading.
The composite specimens were cyclically deformed under fully-reversed, total strain-amplitude-controlled cyclic straining, giving lives of less than 104 cycles to failure.
Investigations with longitudinal stiffeners of the steel grade S700 under fully-reversed, constant amplitude loading and under variable amplitude loading with a straight-line spectrum show impressive fatigue strength improvement by high-frequency mechanical impact (HFMI) treatment.
Investigations carried out under fully-reversed, constant amplitude loading with longitudinal stiffeners of the steel grade S700 show impressive fatigue strength improvement far superior to those observed using other mechanical treatments such as hammering or shot peening.
Fatigue tests were conducted under fully-reversed (R = −1) and positive stress ratios (R = 0.1 and 0.3) with specimens of different thicknesses, different fiber orientations, and at temperatures of −40 °C, 23 °C, and 125 °C.
In the present work, a modified elastic-viscoplastic material model has been fitted to 7175-T7351 alloynium alloy data under fully-reversed uniaxial (strain-controlled) isothermal loading conditions at 160 °C and 200 °C.
As a significant scientific problem directly impacting on the long-term safety of engineering materials and facilities, the improvement of fatigue strength under fully-reversed cycling was comprehensively explored in this study.
The fatigue behavior of two alloys with different grain size was determined by means of uniaxial cyclic deformation tests under fully-reversed deformation (Rε= -1) at 400 °C in the low cycle fatigue Rε= -1.
